Alexander Ian Sharp is an English actor. He is known for originating the role of Christopher Boone in the Broadway production of The Curious Incident of the Dog in the Night-Time. He is also known to a wider audience as Will Downing in 3 Body Problem.

The Curious Incident of the Dog in the Night-Time is a play by Simon Stephens based on the novel of the same name by Mark Haddon. During its premiere run, the play tied the record for winning the most Olivier Awards (seven), including Best New Play at the 2013 ceremony. The play is a National Theatre Production, in association with Frantic Assembly, who specialised in the movement direction.